Integrated Circuit Active Power Supply Regulation

Abstract

Method and apparatus for compensating for voltage fluctuations on a voltage supply line in an integrated circuit device. In accordance with some embodiments, the apparatus includes a voltage fluctuation sensor which senses a voltage on the supply line, and a compensation circuit comprising a switch and a charge storage device (CSD). The switch actively connects the CSD to the supply line when the voltage sensed by the voltage fluctuation sensor passes outside a predetermined voltage range.

1 . A method comprising:
 sensing a voltage on a voltage supply line in an integrated circuit; and   using a switch to actively connect a charge storage device (CSD) to the supply line when the sensed voltage transitions beyond a predetermined voltage range.   
   
   
       2 . The method of  claim 1 , further comprising a step of subsequently using the switch to disconnect the CSD from the supply line when the voltage subsequently returns to within the predetermined voltage range. 
   
   
       3 . The method of  claim 1 , wherein the using step comprises accumulating charge from the supply line on the CSD when the CSD is actively connected to the supply line by the switch to compensate for an overshoot condition. 
   
   
       4 . The method of  claim 1 , wherein the using step comprises transferring prestored charge from the CSD to the supply line when the CSD is actively connected to the supply line by the switch to compensate for an undershoot condition. 
   
   
       5 . The method of  claim 4 , further comprising a step of providing a voltage boosting circuit which supplies a boosting voltage that is at least about twice the voltage on the supply line, wherein the boosting voltage supplies the prestored charge on the CSD prior to said active connection of the CSD to the supply line during the using step. 
   
   
       6 . The method of  claim 1 , wherein the sensing step comprises using a differential amplifier which outputs an amplified AC component of the voltage on said supply line, and a comparator which compares said amplified AC component to a reference voltage threshold. 
   
   
       7 . The method of  claim 6 , wherein the comparator is characterized as an analog-to-digital converter (ADC) which outputs a digital signal in response to said comparison, and wherein the switch of the compensation circuit is moved from a first position to a second position responsive to the output digital signal. 
   
   
       8 . The method of  claim 7 , wherein the digital signal has a first logical state when the amplified AC component is greater than the reference voltage threshold, and wherein the digital signal has a second logical state when the amplified AC component is less than the reference voltage threshold, wherein the switch is moved to a selected one of the first or second positions responsive to the first logical state, and wherein the switch is moved to a remaining one of the first or second positions responsive to the second logical state. 
   
   
       9 . The method of  claim 1 , wherein the voltage on the voltage supply line has a nominal voltage level of about +20.0V or lower. 
   
   
       10 . The method of  claim 1 , wherein the switch of the using step is characterized as a metal oxide semiconductor field effect transistor (MOSFET), and wherein the CSD of the using step is characterized as a semiconductor capacitor. 
   
   
       11 . An apparatus comprising:
 a voltage fluctuation sensor configured to sense a voltage on a voltage supply line in an integrated circuit; and   a compensation circuit comprising a switch and a charge storage device (CSD), wherein the switch actively connects the CSD to the supply line when the voltage sensed by the voltage fluctuation sensor transitions beyond a predetermined voltage range.   
   
   
       12 . The apparatus of  claim 11 , wherein the switch of the compensation circuit subsequently disconnects the CSD from the supply line when the voltage subsequently returns to within the predetermined voltage range to compensate for an overshoot condition. 
   
   
       13 . The apparatus of  claim 11 , wherein the compensation circuit is characterized as an overshoot compensation circuit and wherein the CSD accumulates charge from the supply line when actively connected thereto by the switch to compensate for an undershoot condition. 
   
   
       14 . The apparatus of  claim 11 , wherein the compensation circuit is characterized as an undershoot compensation circuit and wherein the CSD transfers prestored charge to the supply line when actively connected thereto by the switch. 
   
   
       15 . The apparatus of  claim 14 , wherein the undershoot compensation circuit further comprises a voltage boosting circuit which supplies a boosting voltage that is at least about twice the voltage on the supply line, and wherein the boosting voltage supplies the prestored charge on the CSD prior to said active connection of the CSD to the supply line by the switch. 
   
   
       16 . The apparatus of  claim 11 , wherein the switch and the CSD are respectively characterized as a first switch and a first CSD, and wherein the compensation circuit comprises:
 an overshoot compensation circuit comprising the first switch and the first CSD, wherein the first CSD is actively connected to the supply line by the first switch responsive to the voltage on the supply line exceeding an upper threshold, and wherein the first CSD accumulates charge from the supply line to bring the voltage thereon below the upper threshold; and   an undershoot compensation circuit comprising a second switch and a second CSD, wherein the second CSD is actively connected to the supply line by the second switch responsive to the voltage on the supply line falling below a lower threshold, and wherein the second CSD dumps prestored charge to the supply line to bring the voltage thereon above the lower threshold.   
   
   
       17 . The apparatus of  claim 11 , wherein the voltage fluctuation sensor comprises a differential amplifier which outputs an amplified AC component of the voltage on said supply line, and a comparator which compares said amplified AC component to a reference voltage threshold. 
   
   
       18 . The apparatus of  claim 17 , wherein the comparator is characterized as an analog-to-digital converter (ADC) which outputs a digital signal in response to said comparison, and wherein the switch of the compensation circuit is moved from a first position to a second position responsive to the output digital signal. 
   
   
       19 . The apparatus of  claim 18 , wherein the digital signal has a first logical state when the amplified AC component is greater than the reference voltage threshold, and wherein the digital signal has a second logical state when the amplified AC component is less than the reference voltage threshold, wherein the switch is moved to a selected one of the first or second positions responsive to the first logical state, and wherein the switch is moved to a remaining one of the first or second positions responsive to the second logical state. 
   
   
       20 . The apparatus of  claim 1 , wherein the switch is characterized as a metal oxide semiconductor field effect transistor (MOSFET), and wherein the CSD is characterized as a semiconductor capacitor.